Azure Cosmos DB is Microsoft's globally distributed, multi-model database. With the click of a button, Azure Cosmos DB enables you to elastically and independently scale throughput and storage across any number of Azure's geographic regions. It offers throughput, latency, availability, and consistency guarantees with comprehensive service level agreements (SLAs), something no other database service can offer.
Introducing Azure Cosmos DB
Foundations of Azure Cosmos DB with Dr. Leslie Lamport, long
Azure207x - Databases in Azure
How to build globally-distributed, fast, billion-user applications with Azure Cosmos DB